1. Field of the Invention
The present invention relates to a cutting machine comprising a frame which can be hitched to a tractor and carries a cutting mechanism comprising a large cross section rotor equipped with knives which are mounted on axes arranged in pockets provided in said rotor.
2. Discussion of the Background
Machines of this kind are used in particular for cutting scrub and bushes.
In such a machine which is described in patent application FR 2 277 624, the rotor consists of a tubular hollow profile with openings for the passage of the knives. Inserted elements in the form of pockets are fitted in these openings so as to isolate the inner volume of the rotor from the outside. The knives are mounted on axes which are common to several of them. These axes extend along the entire length of the rotor and pass through the side walls of the pockets. The knives are articulated on the segments of the axes which lie in the pockets, so as to be able to turn about them. Thus, the knives of this rotor can be fully retracted within the limits of the outer contour of the body of the rotor when they encounter stumps or other obstacles, so as to avoid damage to the entire machine under the effect of overload. However, with this rotor, the user may have to completely remove an axis and all the knives mounted on it when one of these knives has to be replaced because of wear. These operations of removing and refitting an axis and the corresponding knives are painstaking or even tiresome if said axis is slightly deformed.
In another machine described in patent FR 2 741 775, the rotor consists of a tube with pockets comprising an end cupel and side walls. The latter extend toward the outside of the tube and carry individual axes for the knives. In this case, the axes and the rear parts of the knives constantly lie outside the outer periphery of the rotor. They are thus exposed to impacts with stumps or other obstacles which may lie on the surface of the ground. These impacts may damage the knives and their axes and even cause the entire machine to deteriorate under the effect of overload.
The object of the present invention is to propose a cutting machine which does not have the drawbacks of the known machines.
To this end, a significant feature of the invention consists in the fact that each knife is mounted on an individual axis located in a pocket set back toward the inside with respect to the outer periphery of the rotor and in that this rotor, on at least one side of each pocket, has a concave recess for fitting or removing the corresponding axis.
This arrangement makes it possible for each knife to be removed or refitted independently of the adjacent knives. It is thus considerably easier to replace a worn knife. In addition, the rear parts of the knives and their axes of articulation are protected by the wall of the rotor. When a knife encounters an obstacle, it can retract fully. The rotor can thus pass over obstacles without this causing damage to the knives and to their axes or even to the machine in its entirety.
According to another feature of the invention, each axis of articulation for one knife has a means of fixing to a side wall of the corresponding pocket. This means advantageously consists of a shoulder provided at one of the ends of the axis and which has a hole for the passage of a fixing member. The latter may be connected to the side wall of the pocket in such a way as to immobilize the shoulder and the corresponding axis with respect to said pocket.
According to another feature of the invention, a tube of smaller cross section is housed in the rotor. The pockets in which the knives are mounted are advantageously connected to this tube. The latter thus strengthens the assembly and in particular avoids the rotor becoming deformed if it encounters an obstacle.